The present invention relates to a new and improved construction of a thread guide or thread guide arrangement at a warp or bobbin creel which is of the type having, for each thread, a thread tensioner and a deflection device in order to deflect the thread, during its exit from the creel, in the direction towards a winding machine.
With the classical arrangement of warping machines or beam warping machines, the axes of the bobbins which are mounted upon the creel, extend at least approximately in a plane which is parallel to the axis of the winding machine.
Such arrangement enables a random size selection of the creel in its lengthwise extent, and thus, it is possible to randomly select the number of bobbins. If the bobbins are arranged such that their axes are perpendicular to the axis of the winding machine, then with large number of bobbins the width extent of the creel would correspondingly increase. This, in turn, again would lead to the result that there would exist appreciable deviations of the angle through which the outer threads must be deflected in relation to the inner threads, in order to be able to be formed at the reed into a compact, parallel thread field.
However, such different deflections would render tremendously more difficult the production of and maintenance of as uniform as possible, and additionally, as low as possible tension of the threads of a thread field during winding upon the winding machine. Such is absolutely mandatory in order to produce a qualitatively faultless warp, since the thread tensioners of the outer threads must be differently adjusted, owing to their larger deflection, than those of the further inwardly situated threads and those of the innermost threads, experiencing practically no deflection.
These difficulties and sources of error are eliminated by the previously mentioned classical arrangement, because in such case all of these threads, upon exit out of the creel, are deflected approximately through 90.degree..
Yet, each deflection of a thread during warping or beaming is problematic for different reasons.
Firstly, the thread, due to its deflection between its infeed and outfeed, experiences an increase in tension due to the friction at the deflection device. This tension increase can be determined from cable friction principles and is dependent upon the construction of the deflection device, the material used for this purpose, and of course, also upon the thread quality. Furthermore, an additional factor which appreciably influences the friction, and thus, the thread tension, is that the contamination of the deflection device, which during operation of the system increasingly occurs, or even at that location where the thread always slides at the same location, as such is regularly the case at deflection devices in the form of deflection rods or thread guide eyelets, leads to possible wear of such locations.
Just the last-mentioned factors, influencing the friction behaviour at the deflection locations, are of course again different for each deflection location. Consequently, as to the threads of a creel, combined for instance into a warp section, there prevail within the warp section different tension conditions, negatively influencing the quality of the warped, and analogously, also a beamed warp.
Furthermore, when using eyelets or deflection rods for deflecting the threads, it is possible that with certain thread qualities, especially in the case of glass fibers or threads for instance, fibrillae dam-up during the deflection, and the threads are thus damaged by this phenomenon known as "fibrilla splitting".